Integrated analysis of single-cell RNA-seq and bulk RNA-seq unravels the molecular feature of tumor-associated neutrophils of head and neck squamous cell carcinoma

Background: Head and neck squamous cell carcinoma (HNSCC) is a lethal malignancy with a high recurrence and distant metastasis rate, posing significant challenges to patient prognosis. Recent studies suggest that tumor-associated neutrophils (TANs) can modulate immune cell infiltration and influence tumor initiation and progression. However, the potential clinical significance of TANs in HNSCC remains insufficiently explored. Methods : TANs-specific marker genes were identified via single-cell sequencing data from HNSC. Based on data from The Cancer Genome Atlas (TCGA), a prognostic risk model was constructed using TANs cell marker genes, and the model was validated with data from the Gene Expression Omnibus (GEO) database. The associations between the TANs signature and clinical characteristics, functional pathways, immune cell infiltration, immune checkpoint expression, and responses to immunotherapy and chemotherapy, were then investigated. CCK-8, Transwell and wound healing assays were conducted to assess the functional role of TANs marker molecules. Results : TANs characteristic genes were identified from single-cell sequencing data from HNSCC patients. On the basis of these characteristic genes, a tumor-associated neutrophils-associated signature (NRS) was developed and validated across internal and external cross-platform cohorts through comprehensive procedures. The NRS demonstrated robust and reliable performance in predicting overall survival. Additionally, patients with a low NRS showed enhanced immune cell infiltration, active lipid metabolism, and increased sensitivity to immunotherapy. In contrast, patients with a high NRS exhibited poor prognostic outcomes, advanced clinical stages, and significant associations with HNSCC metastasis and progression. Furthermore, we identified a TANs-associated biomarker, OLR1, and validated that OLR1 promotes HNSCC proliferation, invasion, and migration through CCK-8, Transwell invasion, and wound healing assays. Conclusion : This study has developed a promising TANs-based tool that may aid in personalized treatment and prognostic management for patients with HNSCC.